SQL-DATABASE ERROR

Database error in WoltLab Burning Board (): Link-ID == false, connect failed
mysql error: Connection refused
mysql error number: 2002
mysql version: unknown
php version: 5.6.40-57+0~20211119.60+debian9~1.gbp8a9bd1
Date: 05.05.2024 @ 16:33
Script: /addreply.php?action=quote&postid=13705&sid=9e1b6279024b05e6f924a6f030a7562d
Referer: http://stc-board.de/addreply.php?action=quote&postid=13705&sid=9e1b6279024b05e6f924a6f030a7562d